1. Chilled Water Pump Head Calculation

Loading.... (view fulltext now)

Loading....

Loading....

Loading....

Loading....

Full text

(1)

Project : AGRICULTURE BANK AL EHSAA

HYDRAULIC CALCULATION

FOR

CHILLED WATER PUMPS

TOTAL DYNAMIC HEAD

SUPPLIER

LAMAH EST.

P.O. BOX : 4814 RIYADH 11412 KSA

TEL: 01- 4915826 FAX : 01- 4915927

(2)

Project : AGRICULTURE BANK AL EHSAAHASSA

Head loss calculation using ( 1 ) COLBROOK Formula For CHILLED WATER PUMPS

no. mm m mm GPM l/s 0.2 0 .2 8 .0 2 .0 0 .2 0 .3 0 .9 0 .5 2 .0 1 .0 1/1 m m/s 1/1 1/1 m m m m m A - B 4" GI 102 1 0.1 340 21.4 1 1 1 1 1 5.4 2.60806 266700.48 0.02061 6.99 0.07 1.87 1.94 1.94 B - C 4" GI 102 4 0.1 340 21.4 2 1 1.1 2.60806 266700.48 0.02061 6.99 0.28 0.38 0.66 0.66 C - G 6" GI 154 18 0.1 680 42.8 3 2.7 2.29756 354008.19 0.01882 3.29 0.59 0.73 1.32 1.32 G - I 3" GI 77.9 21 0.1 155 9.77 2 1 1 2 2.04779 159563.45 0.02233 6.13 1.29 0.43 1.71 1.71 I - J 1 1/4" GI 35.1 6 0.1 25 1.58 2 1 1.1 1.62956 57165.116 0.02802 10.8 0.65 0.15 0.8 0.8 J - K 1 1/4" GI 35.1 20.5 0.1 25 1.58 1 0.3 1.62956 57165.116 0.02802 10.8 2.22 0.04 2.26 2.26 K - L 1 1/4" GI 35.1 10.2 0.1 25 1.58 1 0.9 1.62956 57165.116 0.02802 10.8 1.1 0.12 1.22 1.22 L - FCU 1/2" GI 15.8 17 0.1 4 0.25 1 1 1 1 11.4 1.29181 20358.906 0.03621 19.5 3.32 0.97 4.29 4.29 TOTAL 98 1 7 6 4 1 10 5 14

Pressure drop in chiller = 10.00m

Pressure drop in FCU = 1.32m

two way valve loss = 1.00m

total friction loss = 14.21m

Total dynamic head supply = 26.53m

Total dynamic head return = 26.53m

Safty factor 20%= 10.61m

total dynamic head = 63.66m

DN ch e ck va lve L o ss m p e r 1 0 0 m d h (2 ) L o ca l lo ss GH S ta ti c h e a l F L in e r lo ss fa ct o r G lo b e va lve

Local factors of fittings

e lb o w ( 4 5 l e g .) e lb o w ( 9 0 l e g .) 14.21 d h (1 ) L in e r lo ss S tr a in e r d isch a rg e o u tl e t D H To ta l lo ss To ta l h e a l (D H + G H ) / p ip e V M e a n V e lo ci ty RE R e yn o ld s n u m b e r To ta l lo ca l fa ct o rs te e re d u ce r g a te va lve no . p a rt o f p ip e DN N o m in a l d ia m e te r Fl e xi b le ID P ip e I n n e r d ia m e te r L P ip e l e n g th K P ip e r o u g h n e ss Q Fl o w r a te

(3)

m 1.942 2.603 3.921 5.635 6.432 8.689 9.914 14.21 14.21 A ccu m u la ti ve P re ssu re

(4)

CHILLED WATER PUMPS

Project : AGRICULTURE BANK AL EHSAA Page ( 1 )

Head Loss Calculations:

The total friction loss Hs Consist of:

Hs = Hs1 + Hs2 ……….…… (1) Where: Hs1 : Friction loss Inside pipes

Hs2 : Friction loss inside fittings Linear friction loss equation:

Hs = J . L ……… ………... .... (2) J = l . V² / ( 2 g D ) ………..……….. (3) Where: J : linear loss factor

L : length Of the pipe (m.)

l : friction loss factor (COLBROOK-WHITE formula) V : velocity of water (m/s)

g : gravity acceleration (9.81 m/s²) D : pipe inside diameter (m.)

COLBROOK WHITE formula:……….. ( 4 ) 1

sqr(l)

Where: K : pipe inside Surface roughness (m.) D : pipe inside diameter (m.)

RE : REYNOLD’S no. is given as follows: (1/1)

RE = V x D / n ………. ( 5 ) Where: n : water viscosity= ( n = 1E-06 m2/s)

V : velocity of water (m/s) D : pipe inside diameter (m.)

V = Q / A ………...………. ( 6 ) Where: Q : flow rate (m³/s)

A : cross section are of the pipe (m²) Data for the first pipe : 4"GI Pipe type & size 4"

114.3 mm Out side diameter (mm) 6.02 mm Wall thickness (mm) D = 0.1023 m : pipe inside diameter (m.)

K = 0.0001 m : pipe inside Surface roughness (m.) = - 2 x log [ k +

3.7 x D Re x sqr( l ) ) 2.51

(5)

Project : AGRICULTURE BANK AL EHSAA Page ( 2 ) Flow : Q = 340.0 GPM = 21.42 l/s = 0.02142 m³/sec A = p x D2 / 4 = 3.14 x 0.102 ² / 4 = 0.00821 m² V =Q / A = 2.608m/s Re = V x D / n = 2.608 x 0.1023 / 0.000001 = 266700.48 1 sqr(l) x sqr( l )

By solving above equation :

l = 0.02061

Loss m per 100 m = J x 100 = 0.06988 x 100 m = 6.988 m / 100m Pipe length L = 1.0 m

dh(1) Liner loss = J x L = 0.06988 x 1.0 = 0.07 m Local losses equation is given as follows:

HS2 = SUM ZE . V ² / ( 2 . G ) …..……….. (7) Where: G : Gravity acceleration (9.81 m/s²)

V : Velocity of water (m/s) SUM ZE : Sum of local loss factors

SUM ZE = gate valve 1 x 0.2 = 0.2

Flexible 0 x 0.2 = 0 Globe valve 0 x 8 = 0 check valve 1 x 2 = 2 elbow ( 45 leg.) 0 x 0.2 = 0 elbow ( 90 leg.) 1 x 0.3 = 0.3 tee 1 x 0.9 = 0.9 reducer 0 x 0.5 = 0 Strainer 1 x 2 = 2 discharge outlet 0 x 1 = 0

Total local factors =

HS2 = SUM ZE . V ² / ( 2 . g )

DH Total loss = HS1 + HS2 = 0.07 + 1.872 = 1.942 m

Total heal (DH+GH) / pipe = Static head + Friction losses ………. ( 8 ) = 0.0 + 1.942 = 1.942 m 2.6081 X 2.6081 2 x 9.81 0.02061 x 2.6081 x 2.608 2 x 9.81 x 0.1023 266700.5 5.40 ] = 0.06988 m/m = 1.8721 m = - 2 log [ 0.0001 + 2.51 3.7 x 0.102 J = l . V² / ( 2 g D ) = HS(2) = SUM ZE.x V² / ( 2 g ) = 5.4 x

(6)

Project : AGRICULTURE BANK AL EHSAA Page ( 3 )

Data for the second pipe : 4"GI Pipe type & size 4" 114.3 mm Out side diameter (mm)

6.02 mm Wall thickness (mm) D = 0.1023 m : pipe inside diameter (m.)

K = 0.0001 m : pipe inside Surface roughness (m.) Flow : Q = 340.0 GPM = 21.42 l/s = 0.02142 m³/sec A = p x D2 / 4 = 3.14 x 0.102 ² / 4 = 0.00821 m² V = Q / A = 2.608m/s Re = V x D / n = 2.608 x 0.1023 / 0.000001 = 266700.48 1 sqr(l) x sqr( l )

By solving above equation : l =

Loss m per 100 m = J x 100 = 0.06988 x 100 m = 6.988 m / 100m Pipe length L = 4.0 m

dh(1) Liner loss = J x L = 0.06988 x 4.0 = 0.28 m Local losses equation is given as follows:

HS2 = SUM ZE . V ² / ( 2 . G )

SUM ZE = gate valve 0 x 0.2 = 0

Flexible 0 x 0.2 = 0 Globe valve 0 x 8 = 0 check valve 0 x 2 = 0 elbow ( 45 leg.) 0 x 0.2 = 0 elbow ( 90 leg.) 2 x 0.3 = 0.6 tee 0 x 0.9 = 0 reducer 1 x 0.5 = 0.5 Strainer 0 x 2 = 0 discharge outlet 0 x 1 = 0

Total local factors =

HS2 = SUM ZE . V ² / ( 2 . g )

DH Total loss = HS1 + HS2 = 0.28 + 0.381 = 0.661 m Total heal (DH+GH) / pipe = Static head + Friction losses

= 0.0 + 0.661 = 0.661 m Total Head for pipe 1 & 2 = 1.942 + 0.661 = 2.603 m

Other pipes are calculated same as above, All data and results are arranged in the following table : 0.02061 x 2.6081 x 2.608 2 x 9.81 x 0.1023 ] = 0.06988 m/m = 0.3814 m J = l . V² / ( 2 g D ) = 1.10 HS(2) = SUM ZE.x V² / ( 2 g ) = 1.1 x 2.6081 X 2.6081 2 x 9.81 0.02061 266700.5 = - 2 log [ 0.0001 + 2.51 3.7 x 0.102

Figure

Updating...

References

Updating...